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The Contact sample is a valuable resource for the MobiLink developer. It provides you with an example of how to implement many of the techniques you will need to develop MobiLink applications.
The Contact sample application includes a SQL Anywhere consolidated database and two SQL Anywhere remote databases. It illustrates several common synchronization techniques. To get the most out of this chapter, study the sample application as you read.
Although the consolidated database is a SQL Anywhere database, the synchronization scripts consist of SQL statements that should work with minimal changes on other database management systems.
The Contact sample is in samples-dir\MobiLink\Contact. For an overview, see the readme in the same location. (For information about samples-dir, see Samples directory.)
The synchronization design in the Contact sample application uses the following features:
Column subsets A subset of the columns of the Customer, Product, SalesRep, and Contact tables on the consolidated database are shared with the remote databases.
Row subsets All of the columns but only one of the rows of the SalesRep table on the consolidated database are shared with each remote database.
Timestamp-based synchronization This is a way of identifying changes that were made to the consolidated database since the last time a device synchronized. The Customer, Contact, and Product tables are synchronized using a method based on timestamps.